Improvement in steam-engine govebnobs



Gr. lV. DAVIS AND G. A. ROLINS, OF NASH-UA, NEW HAMPSHIRE.

Letters Patent No. 64,500, dated Mag/7,1867. i

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TO ALL WHOM IT MAY CONCERN:

Be it known that We, GEORGE W. DAVIS and GEORGE A. ROLLINS, of Nashua,in the county ofl Hillsborough, in the State of New Hampshire, haveinvented a new and useful Improvement in Means of Regulating andWorkingSteam Valves as Cut-Offs; and We do hereby declare that thefollowing is a full and exact description thereof, reference being hadto the accompanying drawings, and to the letters of reference markedthereon, in which- Figure I is an end elevation.

Figure 2 is an end elevation and vertical section through valvechest.

Figure 3 is a view of the Working parts of the eut-off detached.

A represents the bed-piece, to which is attached the steam-cylinder B Cis the steam-chest and valve-box D is a hollow shaft supporting thegovernor; E is a rocker-arm connected with the governor by means of therod O; H is a shaft on which are fixed the armsfg; z' are linksconnected with arms g and valve-lit`ters J; m are cross-heads on the endof the valve-stems n; I is a shaft revolving coincident to thecrankshaft in the direction of the arrow, fig; 3, on which are fixed therevolving eecentrics K, and the valve-lifters J. Said litters are heldin position by the links z', arms y, and shaft H. In hg. 1 thevalve-lifter J is represented in `position for lifting the valve to itsextreme height. lFig.4 2 represents the lifter J in the act of loweringthe valve on to itsl seat, it'being held against the inclined circle onthe valve-stem cross-heud m, by means of links z' and arm g, the centresof said links and arm being nearly on a line with the centre of theshaft H. The object ofso placing the linkszl and arms g is to hold thelifters more firmly, while the valves aro closing, therebyF relievingthegovernor; also that the centres or turning-points of the links whichare attached to the arms g may be lowered in proportion as thegovernor-balls diverge from the cont-re, thereby causing the points ofthe Iifters to slide oli" of the lifting-points on the cross-headsquicker in proportion as said balls diverge', and when the balls are attheir highest points the valve-litters will not come in Contact With thecross-heads, and the valves are not lifted, as shown in fig.

lVhat We claim, and desire to secure by Letters atent, is-

The revolving eccentric K, litters J, links z', arms g, in combinationwith the gevernorffor tlre purpose of operating steam-valves assubstantially herein set forth.

G. W. DAVIS, GEO. A. ROLLINS.

Witnesses:

JOHN B. PERKINS, Guo. Y. SAWYER, Jr.

